This paper obtains an exact solitary wave solution of the Korteweg-de Vries equation with power law nonlinearity with time-dependent coefficients of the nonlinear as well as the dispersion terms. In addition, there are time-dependent damping and dispersion terms. The solitary wave ansatz is used to carry out the analysis. It is only necessary for the timedependent coefficients to be Riemann integrable. As an example, the solution of the special case of cylindrical KdV equation falls out.